Value-added assessment is a system of following individual students over time, measuring their progress each year against previous years. Value-added assessment shows potential for measuring teacher effectiveness as well.
When students are seen to make significantly more progress with certain teachers than with others, it points to teachers who are effective with a variety of students. Studying recent research data from the Dallas Independent School District, researchers Sitha Babu and Roberto Dendro looked at the impact of effective teachers.
They designated as effective those teachers whose students consistently scored in the top 40 percent on fourth-grade tests and as ineffective teachers whose students score in the bottom 40 percent on these tests. They determined the impact of teachers on students’ performance by analyzing how well students did three years later on the state-mandated seventh-grade test.
Results showed that after three consecutive years with effective teachers, virtually all students at any achievement level passed the seventh-grade test. Three years in a row of ineffective teachers had little impact on middle- and high-achieving students (they passed the test with average scores of 89 and 90 percent).
Impact on low-achieving students
But consecutive years with ineffective teachers had a devastating effect on the performance of already low-achieving students. Only 42 percent of low-achieving students passed if they spent three years in classes with teachers identified as ineffective. These results suggest that low-achieving students are much more dependent on effective teaching for developing the skills necessary to pass a state-mandated tests than are average- or high-achieving students.
Therefore, matching effective teachers with the lowest-achieving students is one strategy to raise test scores across a district. Unfortunately, studies show that without such intentional placement, low-achieving students are much more likely to be in classes with ineffective teachers. If one definition of good teaching is that it raises test scores, then value-added measurement can help identify effective teachers.
“Value-Added Assessment Findings: Poor Kids Get Poor Teachers,” Phi Delta Kappan, Volume 8, Number 4, December 2004, pp. 331-333.
Published in ERN February 2005 Volume 18 Number 2